Rotary toothbrush



April 14, 1942. H. L. GLYNN ROTARY TOOTHBRUSH Patented Apr.l 14, 1942 UNITED l' STATES PATENT OFFICE ROTARY 'roornmwsn Henry L. Glynn, st. Laux., Mu.

Application March 15, 1939, Serial No.' 261,888

said control means to determine the proper ro- 6 Claims.

This invention applies to a toothbrush of the rotary type. More particularly the invention is concerned with operating a rotary brushing element in such a manner as to control its rotation in accordance with the brushing operation which is to be performed.

Dentists recommend brushing the teeth mostly with a vertical movement of the brush, and it is by the manner in which the brushing element.

is applied to the mouth.

Another object is to provide an improved structure for such a toothbrush which will render the same reliable in operation and simple in construction.

Further objects will appear from the following description taken in connection with the accompanying drawing in which Figure 1 is a side View partly in section illustrating a toothbrush embodying this invention.

Figure 2 is a section on line 2 2, Figure 1,

Figure 3 is a somewhat enlarged, sectional detail of Figure 2 as seen from below, taken on line 3-3 of Figure 2.

Figure 4 is a sectional ldetail of the brushing element and the guard therefor.

Figure 5 is a diagram of electrical connections and,.

Figures 6 and 6a show diagramatically the manner of operation of the device in controlling the direction of rotation.

Figures l and 7 disclose a cross sectional vand plan view, respectively, of the device brushing the tops of the teeth.

In accordance with this invention, a rotary brushing element is provided which may be driven by any suitable type of driving means. An electric motor is a convenient driving device for this purpose. of rotation of the brushing element, control means are-provided extending adjacent that element so as to contact with the mouth, usually the gums, when the brushing element is applied to Athe teeth, such contact operating to 'move In order to control the direction.

tation oi' the brushing element. This may be accomplished in a convenient manner by providing a guard for the brushing element so positioned as to contact with the gums when the element is applied to the teeth, such contact rotating orotherwise moving the guard. The movement of the guard is arranged to operate rotation control means, such, for instance, as a reversing switch in the case where an electric driving motor is employed.

Referring now to the drawing, I designates a suitable housing which may also provide a handle for manipulating the device in operation. Driving means of any suitable type such as a motor 2 may be housed with the housing I and provided with a shaft 3 suitably connected to drive the brushing element.

In the embodiment illustrated a brushing element 4 of any suitable type provided with a spindle 5 is mounted for connection to be driven by the' shaft 3. A guard 6 is arranged to partly,

surround the brushing element 4 but is provided with an opening or gap 'l through which the element 4 may protrude so as to be able to engage the teeth. The guard 6 is mounted for rotary movement around the axis of the spindle 5 to a limited extent and such movement is arranged to operate controlling means presently to be described for controlling the direction of rotation of the motor 2.

As shown in Figure 6 the edges of the guard 6, which may be provided with soft pads 8 of any soft material such, for instance, as rubber, are brought into contact with the gums or other suitable part of the mouth as indicated, for instance,

at 9, such contact operating to rotate the guard 6 on its axis. The left-hand side of Figures 6 and 6 illustrate operation on the outside surfaces Of the teeth, while the right-hand side illustrates operation on the inside surfaces. Figure 7 illustrates operationen the upper surfaces of the lower teeth, the inset showing a sectional view. In this case the brush may be placed directly over the teeth and the device turned until the guard 6 engages one of the front teeth to determine the direction of rotation. The brush may then be moved across the top surface. The under surfaces of the upper teeth may be brushed in a similar manner.

The guard 6 may be mounted upon a suitable carrier l0 mounted to swivel about the axis of the shaft 3. The carrier I0 may be mounted in any suitable bearings such as ball bearings Il and I2. The bearing i2 in the construction illusy switch for controlling the motor 2.

trated is seated against a shoulder I3 formed in a ring I4 of insulating material such as, for instance, Bakelite. The ring I4 in turn is seated at I5 upon the housing I. The outer ball bearing II is centered by a guide bushing I6 also of insulating material such as. Bakelite which in turn is seated at I1 upon the ring I4. A screw cap I8 threaded at I9 on the housing I serves to retain the bushing I6 and the ring I4 in place on the housing and also engages the outer'race of the ball bearing II so as to retain said bearing against endwise movement.

The parts I0, I4 and I6 carry a reversing The ring I4 carries two sets of reversing contacts as illustrated in Figures 2 and 3. Mounted in the bushing I6 are contacts 20 and 2|. 'I'hese are preferably constructed of very thin strips of spring metal. The outer ends thereof are bent outwardly as indicated at 22 to form contact faces. These may be faced with a suitable noncorrosive metal such as tungsten, beryllium or theV like' to withstand arcing. These contacts may be mounted in any suitable manner in the bushing I6. A simple way is to mold a portion of the contact into the material when the bushing is formed as, for instance, at 23. A third constructed having its contacting ends 25 bent upwardly as shown in Figure 3 so as to be positioned opposite the contact faces 22. The contact 24 may be provided with a stem 26 embedded in the ring I4 so as to support the contact in said ring. Mounted in any suitable manner on the carrier I is an arm 21 extending outwardly and provided at its outer end with a bridging contact 28 positioned between the ends of the contacts 20, 2l and 24, and having tapered ends facing the respective contact faces 22 and 25 so that by movement in one direction or the other the bridging contact 28 will connect the contact 24 with one or the other of the contacts 2li or 2|. The arm 21 is preferably very flexible so that the contact 28 may adjust itself to the contact faces 22 and 25. The ring I4 and the bushing I6 may be provided with suitable recesses 29 and 30 respectively adapted to accommodate the contact devices just described. This contact switch is duplicated-at a diametrically opposite point as indicated in Figures v1 and 2. The contacts 20 and 2l may be provided with stems 3l and 32 respectively which together with the stem 26 are arranged to pass through the ring I4 as well as a bearing bracket 33 in the housing I and to engage receiving contacts 34 within the houss ing I. All the motor connections may be brought to the contacts 34 in proper arrangement so as to be connected to the switches in proper order when the stems 26,G 3I and 32 engage the contacts 34.

The motor connections may be arranged as shown in Figure in lwhich the contacts of the upper switch are numbered as in Figure 3, while those of the lower switch have corresponding numbers with the letter a" added. It should be noted that when the carrier I0 is rotated the arm 21 moves in one direction as shown in Figure 5, while the arm 21a moves in the opposite direction as if rotating about an axis between the two. It will be seen that by this arrangement movement of the carrier I0 in one direction or another will operate the switch to cause forward or reverse rotation of the motor 2. The

36 in the ring I4. This spring serves to resiliently center the'carrier I 0 with both switches with an inwardly directed bead 36 engaging Ia Acontact indicated generally at 24 is similarly carrier Iii is further provided with a light spring groove in the carrier I0. The end of the guard may be slotted as shown at 31 to render the end resilient in order to slide over the end of the carrier I0. Said carrier may also be provided with a lug 38 adapted to enter the slot 31 so as to position the. guard 6 properly with respect to the carrier and the switch. The spindle 5 of the brushing element 4 may be connected to the shaft 3 by any suitable type of insulated coupling 39 adapted to rotate freely within the bore oi' the carrier I0. An easily releasable connection between the spindle 5 and the coupling 39 is preferable so that the spindle and guard may be removed simply by pulling the latter oi of the carrier I0.

The guard 6 may be provided with an outer bearing 40 adapted to receive a suitable journal on the end of the spindle 5. The spindle 5 may be constructed of flexible wire and provided with a shank 4I attached to the spindle and providing means for attaching the same to the shaft 3. The shank 4I may be in the form of a sleeve fitting over the end of the spindle 5. The shank may be provided with a collar 48 bearing against the plug 42 to retain the journal resiliently seated in the bearing 40. To dissemble these parts it is only necessary to pull the guard and spindle off of the carrier I0 and shaft 3 respectively, and then, by pushing the spindle back against the plug 42, release the journal 41 from the bearing 40. Thereafter the ilexbility of the spindle 5 permits the same to be flexed outwardly to clear the bearing 40 and then pulled out of the plug 42.

In order to prevent the liquids used in treating the teeth from running down the guard 6 into the housing a plug 42 may be provided within the guard. This may be constructed of any suitable material such as soft rubber and arranged to have a light contact with the spindle 5- so that the latter may rotate therein practical ly without friction. At the same time the plug provides a seal between the spindle and the guard so as to stop the iiow of liquids along the spindle.

It will be seen, therefore, that the invention accomplishes its objects by providing a rotary brushing device which will always brush the teeth in the proper direction. As noted in Figure 6 at A when brushing the upper teeth the upper edge of the guard 6 contacts with the gums causing rotation of said guard in a counter-clockwise direction as seen in that figure. This operates the switch so as to cause the motor to rotate in such a way as to turn the brushing element 4 in a clockwise direction so as to brush the teeth downwardly. On the other hand as shown at B when brushing the lower teeth the lower edge of the guard 6 contacts with the gums to rotate the guard in clockwise direction, thereby reversing the switch and the direction of rotation of the motor so as to cause the brushing element to rotate in a clockwise direction. This causes the brushing element to brush the lower teeth upwardly as is desired. It will be noted that the control of the direction of brushing the teeth is entirely automatic and requires no attention by the operator. Furthermore, it is practically impossible to Lush the teeth in the wrong direction.

It will` further be noted that the construction is such that the device is easily disassembled for cleaning and can, therefore, be kept in a sanitary condition.

As some types of motors used for the driving motor 2 tend to run at excessively high speeds, and it is desirable to brush the teeth with the elementi running at a moderate speed, it is con venient to have means for-limiting the motor speed. Toward this end a steel ball l5 is arranged to bear against the left-hand end of the shaft 3, Figure 1. An adjusting screw I8 may be provided to adjust the pressure oi' the ball I5 against the shaft 3 whereby to introduce `suiiicient friction to limit the motor speed tothe desired value. 1f desired a spring may be introduced between the screw 46 and the ball 45.

While this invention has been described as embodied in a unitary device it will be understood that individual features orsubcombinations thereof may be useful by themselves without reference to other features or the complete combination, and that the employment of such individual features or subcombinations is contemplated 'by this invention and within the scope of the appended claims. It is further obvious that various changes may be made in the details of construction within the scope of the appended claims without departing from the spirit of this invention, and it is understood, therefore, that the invention is not limited to the specific details shown and described. Havingthus described the. invention cwhat is claimed is:

1. A rotary toothbrush, comprising, rotary driving means, a rotary brushing element adapted for brushing engagement with the teeth and having a spindle connected with said driving means, means mounted adjacent said brushing element and movable by contact with the mouth in the course of brushing, and means operable by said movable means to control the rotation of said brushing element.

2. In a rotary toothbrush having rotary driving means, a rotary brushing element having a spindle connected with said driving means, a guard for said brushing element mounted for rocking movement with respect to said spindle, and means operable by movement of said guard to control the rotation of said brushing element.

3. A rotary tooth brush, comprising, an elecn tric driving motor, a rotary brushing element, adapted for brushing engagement with the teeth and driving connections lfrom said motor to said element, means mounted adjacent said element and movable by contact with the mouth in the course of brushing, .and a switch operable by said movable means to control the operation of said motor.

4. In a, rotary tooth brush, an electric drivingr motor, a rotary brushing element, driving connections from said motor to said element, means mounted adjacent said element and movable by contact with the mouth, and a switch operable by said movable means in accordance with the di'- rection of movement thereof to control the operation of said motor in a corresponding direction. 5. In a rotary toothbrush, an electric driving motor, a rotary brushing element, driving connections from said motor to said element, a guard for said brushing element mounted for rocking relative thereto, and a switch operable in accordance with the direction of movement of said guard to control the operation of said motor in a corresponding direction,

6. In a rotary toothbrush having rotary driving means, a rotary brushing element having a spindle connected with said driving means, means. 

